Containerised handling of bulk materials and apparatus therefor

ABSTRACT

A freight container ( 10 ) has a base ( 20 ) or a portion thereof that can be opened to discharge its contents. This container ( 10 ) has a top which can be opened in similar manner as the base. Another container having at least one compartment, each compartment having a lower section with a reducing cross-sectional area and a pivotably operable closure assembly, with several such closure assemblies being linked together by means of bars. Such a container is used to contain raw building materials for stockpiling of these materials at a container port. It is also used to supply materials to a concrete production plant whee pollution control containers are provided below the supply container and above the scaling and mixing stations to reduce particulate pollution. A pair of slewing apparatuses is also provided to engage both ends of a container and turn the container over about its longitudinal axis, thereby emptying its contents.

FIELD OF THE INVENTION

[0001] This invention relates to containerised handling of bulkmaterials, for instance raw building materials. It also relates tostockpiling and batching of such materials using containers in general.

BACKGROUND OF THE INVENTION

[0002] Containers can be used to carry bulk materials, for instance rawbuilding materials. However, one problem with this is that suchmaterials are not always easy to unload. The containers tend to betipped up from one end, so that the materials fall out of the other.However, this is not just a simple matter of tipping by a few degrees.Some materials require a tipping angle of over 45° to be fully unloaded.This requires tipping equipment and space and moreover can cause a lotof dust and mess.

[0003] An alternative to using a normal box container is to use a tankor silo container (with the tank in a container frame). The materialsthere are emptied through valves at the base. Whilst this may work fordry materials, it tends not to work for damp ones; the valves clog up.

[0004] The transportation of bulk materials is well exemplified byconcrete. Concrete is a common construction materials and is a compositeof cement, sand, gravel and water. The strength of cured concretedepends on the proportions of each component. Additives may be added toimprove the fluid properties of the concrete during mixing and/orcasting; others may be added to improve the hardness of the concreteafter curing; colour pigments can also be added to give the concrete adistinct colour for a specific application, such as to differentiate thefloor areas at a factory.

[0005] These raw materials are normally supplied in bulk by separatesuppliers. For example, cement is manufactured only at a specialisedplant, where limestone and large electric power are readily availableand only at the locations approved by the environmental authorities.Similarly, gravels are produced at the quarries and the industry is alsocontrolled by the environmental authorities. Sand may be dredged outfrom the sea or river bed. These raw materials are then transported to abatching plant. This may be at a construction site, but in many cases,there is no land available for an on site concrete batching plant orthere may be other reasons why it is not feasible. In such cases, theraw materials are batched at a remote batching plant and transported tosite by concrete mixers. This remote batching plant may have to occupy alarge piece of land to stockpile the raw materials. In land-scarcecountries, such as in Singapore, efficient use of land is a concern.

[0006] In many places, all the raw building materials are imported fromthe surrounding regions; gravel may come from one place with sand andcement coming from again different places. Typically, gravel and sandare transported by barges, while cement by specialised ship. At thelanding point, these materials are stockpiled and then transferred tothe batching plants or construction sites.

[0007] These batching plants and landing points are normally openfacilities and the transfer of huge amounts of materials generates a lotof dust into the air. Abatement of dust pollution is thereforeimportant.

[0008] Tipping of a container mounted on a truck tends to cause a lot ofdust. Also tipping of a container suspended on a crane is not a safepractice. Shipping of wet sand and gravels in silo or tank containersdoes not work.

[0009] These problems necessitate a search for simpler and economicalmeans of shipping and transfer of bulk materials and yet reducingpollution from the present levels.

SUMMARY OF THE INVENTION

[0010] This invention provides novel containers and, inter alia, anapparatus and system for containerised handling of raw buildingmaterials. These containers are handled at a container port and arestockpiled at the stacking yard. Sand and gravel (aggregate) can also bebatched into mixer containers for stockpiling.

[0011] According to a first aspect of the present invention, there isprovided a container for transferring bulk materials, being shaped,dimensioned in length and width and operable as a standard freightcontainer and having a base, at least a portion of which is openable fordischarging contents of the container therethrough.

[0012] The base or a portion thereof can be slidable, pivotable, hinged,swingable, displaced vertically, etc.

[0013] Preferably, the container has at least one compartment, the oreach compartment having at least one lower section of reducingcross-sectional area, each leading to an opening, and a closure assemblyfor the or at least one opening, for releasing or retaining thecompartment's contents. Moreover, the or at least one closure assemblyis preferably pivoted.

[0014] According to a second aspect of the present invention, there isprovided slewing apparatus for turning a container comprising:

[0015] a supporting portion;

[0016] a rotatable, container holding portion; and

[0017] means for rotating said container holding portion on saidsupporting portion; wherein

[0018] said container holding portion comprises:

[0019] a base portion for supporting and fastening to the lower part ofa container; and

[0020] arm means extensible in a first direction and having fasteningmeans with an extent in at least a second plane, orthogonal to saidfirst direction, for fastening to the upper part of a container;

[0021] wherein said fastening means is rotatable between a firstposition where it cannot fasten said container, whilst the container issupported and fastened to said base portion, and a second position,where it can fasten said container, whilst the container is supportedand fastened to said base portion.

[0022] Preferably, when said fastening means is in said first position,a container can be placed for fastening to said base portion or removedtherefrom, and, when said fastening means is in said second position,the fastening means obstructs a container from being placed forfastening to said base portion or removed therefrom.

[0023] Advantageously, the base portion may be arranged to support acontainer from below and said fastening means arranged to fasten to acontainer from above.

[0024] Preferably two such apparatus are used together, one for each endof a container.

[0025] A pollution control enclosure for use with the slewing apparatusis also provided.

[0026] According to another aspect of the invention, there is provided asystem for producing a mixture of components, comprising:

[0027] at least one stocking section having a stocking chamber for acomponent; and

[0028] a scaling section for determining and delivering a scaled amountof each component;

[0029] and operable such that a container may be stacked on top of saidstocking section for replenishing said component therein.

[0030] This system for producing a mixture of components, may furthercomprise a section for holding or blending the scaled components beforedischarging the mixture.

[0031] This could be by using a container as above or the slewingapparatus as above.

[0032] Preferably the system includes a pollution control section foruse between at least said container and said stocking section forabating particulate pollution as material is discharged into thestocking section.

[0033] The stocking section, scaling section, mixing section and the oneor more pollution control sections ideally are shaped, dimensioned,transportable and stackable as a standard freight container.

[0034] This system is advantageous for producing concrete.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described by way ofnon-limitive examples with reference to the accompanying drawings, inwhich:

[0036]FIGS. 1a-1 c show containers having a sliding base plate in one ortwo parts, according to one aspect of the invention;

[0037]FIGS. 2a-2 e show containers having a hinged base plate in one ortwo parts, according to embodiments of the invention;

[0038]FIGS. 3a-3 b show a compartmentalised container, being anotherembodiment of the invention;

[0039]FIGS. 4a-4 b show a container with both a base and top that can beopened;

[0040]FIGS. 5a-5 e show details of containers according to furtherembodiments;

[0041]FIGS. 6a-6 f show details of containers according to yet moreembodiments;

[0042]FIGS. 7a-7 c show a slewing apparatus for a container according toanother aspect of the invention;

[0043]FIGS. 8a-8 g show a system for containerised handling of rawbuilding materials at a concrete production plant, according to yetanother aspect of the invention;

[0044]FIGS. 9a-9 c show a pollution control enclosure for a slewingapparatus;

[0045]FIG. 10 shows another system for containerised handling of rawmaterials at a concrete production plant;

[0046]FIGS. 11a-11 d show interfacial seals between stacked-upcontainers, according to again another aspect of the invention;

[0047]FIGS. 12a-12 c show covers for preventing waste of raw materialsaccording to yet again another aspect of the invention; and

[0048]FIG. 13 shows a system for containerised handling of raw buildingmaterials at a port.

DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

[0049]FIG. 1 shows a container 10 with a single sliding base plate 20.This container 10 has the same or similar external length and widthdimensions and corner castings as a regular freight container already inuse, such as that of an ISO-type or SeaLand-type container. The heightcan be non-standard, although standard heights may be preferred.However, the base is different, allowing the base plate 20 to slideopen. In this manner materials within the container can fall out of thebottom. The base frame of the container has support bars 30 supportingthe base plate when closed and keeping it rigid under the weight of theraw materials. These support bars 30 are preferably pointed or curved atthe top to prevent material settling on them when it falls.

[0050] Additionally, around the edges of the base plate 20, there areseals 15 to prevent material in the container getting around the endsand sides of the base plate 20 and escaping or clogging up the slidingaction.

[0051] The base plate 20 need not be a single piece. It can be made oftwo pieces 20′, 20″ as shown in FIGS. 1b and 1 c, preferably with anoverlapping edge 21. This has the advantage that the opening of the basecan be carried out from either or both sides, if and when spaceconstraints require it. A single container can have two or moreindependently movable or immobile base plates along its length and/orits width. There may be containers where the split is not central and/orwhere one side is immobile.

[0052] In another embodiment of this invention, FIG. 2a shows a hingedbase plate 22 instead of a sliding one. Preferably, this hinged baseplate comprises two pieces 22′, 22″ as shown in FIG. 2b, with the pivotaxes along the base struts of the container frame and the overlappingedges substantially mid-way in between. For a long container, such as atwenty-footer, it is possible to have the hinged base plates across thecontainer in several sections 24 so as to ensure rigidity of the base(see FIG. 2c). It is also possible that a strut 31 be provided along thecentre(s) of the base frame(s) of the container, in either the long orthe short section. In this way, the moving edges of the base plates mayabut the centre strut 31 offering more secure locking and releasingmechanisms and greater strength. The hinges may be located at struts 31instead of the edge struts of the container (FIGS. 2d and 2 e).

[0053] A further embodiment compartmentalises the container 10′ tohandle various raw building materials at the same time (FIGS. 3a and 3b). In this way, for example, sand and/or gravel (aggregate) can bebatched into different compartments of a container. With this provision,it is possible to supply a container of sand and aggregate to a blendingstation to produce concrete with different structural strengths (havingdifferent compositions of sand, aggregate, cement and water). Withprescaling of each batch of material, it is also possible to do awaywith the scaling station at a typical cement batching plant. Threecompartments are shown but there may be any other number withcompartments separated along the length and/or width of the container.

[0054] A further embodiment is shown in FIGS. 4a and 4 b, which has atop that can be similarly opened. This feature allows easy loadingwhilst afterwards covering its contents, especially sand, and ensuresthat the moisture content is maintained during shipping or stockpiling.

[0055] The sliding action of the base plate (or sections of it) can beachieved by means of built-in hydraulic cylinders and a (remote)hydraulic power unit. This method is preferred for the large power thatit can deliver, yet the cylinders are compact enough for installationbelow the base plate. With some compact control units, installed at anedge of the container for example, an operator can easily operate thecylinders to slide open the base plate. By operating different controlunits, different sections of the base plate can be opened. The cylindersand control units may be connected at least in some parts by flexiblehoses that are in common use. The flexible hoses allow relative movementbetween the cylinders and control units thereby making the opening ofthe base possible. The control unit may be integrated with the powerunit.

[0056] In the same manner, hydraulic cylinders, for example, may be usedto release the catches of the locks for the hinged base plate orsections of it. Hydraulic power is preferred, due to its huge power,compact cylinders and control units, and flexible power lines.Additional hydraulic cylinders may be provided to enable closing of thehinged base plate. This is particularly useful when access to close thehinged base is not possible for safety reasons, for example.

[0057] The movable base plates are also provided with handles, whichallow them to be pulled from outside, for example by a hook on a chain,a forklift. Other means, especially rotary means, such as a motorconnected to a reduction gear set driving a rack and pinion assembly; ora winch and cable mechanism may be used.

[0058] It is also possible that the actuators (both linear and rotary)for operating the base plate (or sections of) of container 10, 10″ aremounted in the structure on which container 10, 10″ sits. In this case aprojection at the moving end of the actuator engages with a catch on thelower side of base plate 20 (or sections 20″ of it). The advantage ofthis feature is that only one set of operable mechanism is required ateach material discharge point.

[0059]FIGS. 5a and 5 b show yet another embodiment of a container fordischarging its content through an openable base, the details of whichare shown in FIG. 5c. The container 10′″ is illustrated with threefunnel portions in its lower part, which are sealed by operable pivotingbase plates 32. Pulling a pivoting base plate 32 to one side allows thematerial in the container to fall out through the end of the funnel. Inthis embodiment, the three pivoting base plates 32 are interconnected,such that pulling one aside, pulls all three. However, in some otherembodiments, especially where the container is compartmentalised, thiswould not be so. Of course there do not have to be three of thesefunnels and opening portions. There could be any number, from oneupwards.

[0060] As can be seen from FIGS. 5a to 5 c, each pivoting base plate 32,is made up mainly of two vertical end hinge plates 32 a, one at eachend, and an interconnecting base portion. The base portion has, as itsupper part, an arcuate closure plate 32 b. The centre of the closureplate 32 b is its lowest part. Below this is a triangular supportstructure 32 c. Two of the apices of the support structure 32 c arecommon to the ends of the arcuate closure plate 32 b. The third apex isbelow the centre of the closure plate 32 b, this being its lowest point.

[0061] The main part of the closure plate 32 b closes off the base ofthe funnel portion 33, thereby preventing material from passing out. Theends of the closure plate, however, extend beyond the edges of thefunnel to ensure complete closure. Seals 38 on each side preventmaterials slipping between the end of the funnel and the closure plate.

[0062] The vertical end hinge plates 32 a are pivoted to the outside ofthe funnel 33, allowing them to swing to either side. In so swinging,the interconnecting closure plate also swings to one side, therebyopening the funnel. The arcuate shape of the closure plate is centred onthe pivot axis of the end hinge plates 32 a to allow it to swing pastthe edges of the funnel without allowing any material to get betweenthem. However, this is not essential.

[0063] The end plates are shown as solid, but could mainly consist ofbars around its edges instead. They are shown as hinged to the funnel33, but could be hinged to the container walls or other struts. Funnels33 are shown as narrowing in two orthogonal directions, but do not needto. They need only narrow in the direction of swing of the closureplate. In the other orthogonal direction they only need to allow the endplates to pivot outside them.

[0064] The closure plates are shown as being perforated. Perforations 32d allow water collected in container 10′″ to drain out and maintain themoisture of the material. Below the perforated closure plate 32 b is afilter material 32 e, such as a sponge, for example. The filter material32 e allows water to pass through but keeps the material inside thecontainer. Inside support structure 32 c is a sloping plate 37. Plate 37keeps filter material 32 e in place and directs water to port 32 f. FIG.5b shows two sloping plates 37, 37′ but may, for example, have only onesloping in one direction. A hose or pipe may be connected to port 32 fto direct water beyond the container boundary, thus preventing waterfrom the upper containers dripping into the lower containers.

[0065] The opening mechanism will now be described. A hook 34 is pivotedon support structure 32 c at pivot 34 a. Pulling the hook pulls thepivoting base plate 32. In order to open all the compartments ofcontainer 10′″ at the same time, link bars 36 are provided between theindividual pivoting base plates 32. These are pivoted on the supportstructure 32 c at pivot points 36 a. The pivot points 36 a and 34 a maywell be common, if required. In addition, springs 36 b, 36 b′ areprovided between the funnels and hooks 34 and/or link bars 36 to returnthe pivoting base plates 32 to their closed positions.

[0066] A remote activation bar 35 below the container 10′″ may be usedto engage hook 34 when container 10′″ is lowered to its dischargeposition. Its height is set to push the hook upwards during lowering, topull the base plates 32 open, thereby opening the base of container 10′″and allowing its content to fall out. The height of activation bar 35 isadjustable. This allows for easy control on the opening of bases 32.Once the container 10′″ is emptied and the container is hoisted up,bases 32 return to their closed position by gravity (and springs orother biasing means).

[0067] In order to reduce the load on the base 32, the area of theopenable base should be kept low, whilst allowing the contents to bedischarged in a controlled manner and within a reasonable rate. Thisalso means that the base 32 should be of a reasonable size and mass.

[0068] An alternative mechanism for opening the pivoted base plate 32 isto replace the remote activation bar 35 with an actuator 35 a, such as apneumatic or hydraulic cylinder as shown in FIG. 5d. Once thereplenishing container 10″ is placed at the material discharge point(which can be a container), actuator 35 a is extended and engaged withthe catch fixedly mounted on base plate 32, thereby turning it about itspivot and opening the base of the compartment of container 10″. Linkbars 36′ may be used to link the base plates 32 of two or morecompartments.

[0069] A variation of the opening mechanism is to mount the actuator 35a′ directly to container 10″ as shown in FIG. 5e. This may be usefulsuch as when the lifting facility has limited headroom.

[0070]FIGS. 6a and 6 b show yet another embodiment of a container 10″for discharging its contents through an openable base. As illustrated inthese figures, the base of the container comprises a plurality of pairedinclined plates 25 extending across the base of the container and spacedapart from each other. These plates 25 slope at an angle of between 20and 60° to the vertical. They are joined at the upper edges, formingtriangular shaped sections 26 across the width of the container. Thespaces between each pair of these sections 26 form discharge chutes 27through which the contents are discharged. At each end of the containeris another inclined plate 25 whose upper edge is joined to the end walland the lower edge joined to the base. These inclined plates 25,together with the nearest inclined plates of adjacent sections 26 alsoform discharge chutes 27.

[0071] The discharge chutes 27 are kept closed by means oftriangular-shaped covers 28 extending across the width of the container.These covers 28 are substantially symmetrical about the vertical. Thisprofile ensures that the flow of the content creates equal opposingdynamic lateral forces on both sides of a cover, and this ensures thateach cover 28 is located at the centre of the discharge space 27. Thesymmetrical sides of covers 28 also ensure that the lateral componentsof the weight of the content on the cover are balanced whilst thevertical component induces self-closing of the covers.

[0072]FIG. 6a shows actuator means 29 installed vertically in the spacedirectly below covers 28 and part of the container. These actuators areoperable to extend vertically for pushing or lifting the covers fromtheir closed position and allowing the contents to discharge through thespace between the covers 28 and the inclined plates 25. These actuatorsare connected to direction control valves by pipes conveying thecompressed fluid, either pneumatic or hydraulic. These controls (notshown in the figure) are conveniently installed in the void space belowthe triangular sections 26 and are accessible from a side of thecontainer. Of course, a plurality of the actuators may be linkedtogether and are operable as a group from a control valve. Additionalset(s) of control valves may be provided at opposite sides of thecontainer for the ease of operation.

[0073] To prevent wear and tear on the actuators 29 due to the flow ofthe materials discharging from the base of the container, there may beprovided a sacrificial cover 29 a around each actuator. This sacrificialcover 29 a can then be replaced at regular intervals as and whennecessary.

[0074]FIG. 6b illustrates the opening of covers 28 in another embodimentwhen the container is lowered on top of a pollution control container120 (shown in FIG. 8a or 8 b) for discharging its content therethrough.In this embodiment, the actuators 29 do not form part of the containerbut are located as part of or in addition to the pollution controlcontainer 120, at a material landing or discharge site. Similarly, thecontrol mechanisms, such as the pneumatic or hydraulic lines anddirection flow control valves are also located with the pollutioncontrol container 120. This helps to reduce the hardware cost of acontainer of this embodiment.

[0075] Each actuator in FIGS. 6a or 6 b need not be controlled by aseparate control mechanism. They can be linked up in parallel, or evenin series depending on the actuators used. Of course, the number ofactuators or control mechanisms is not a limitation.

[0076]FIG. 6c illustrates another embodiment and the opening of covers28 with the use of fixed activation bars 29 b installed on the pollutioncontrol container 120, instead of an extensible piston means. Thus theact of lowering the container causes the discharge chutes to be opened.

[0077] It is noted that installation of these actuators 29 or activationbars 29 b are not confined to the pollution control container 120. Theycould be similarly installed elsewhere, such as on a stock container104, 110 or discharge container 102 (as described later in FIG. 8)depending on the apparatus adopted for each material handling facility.

[0078]FIGS. 6d and 6 e illustrate yet another method of opening covers28. As shown in FIG. 6d, the top edge of cover 28 has two points spacedapart from each other, to each of which is attached an end of a rope 28a. The other end of each rope is attached to a cross bar 28 b moveablypositioned across the container near the top. The ends of the cross bar28 b have hooks for engaging the top edge of the container. Engaging thecross bars 28 b, for example using additional hooks from the liftingequipment, and hoisting them up a distance pulls the covers 28 up,thereby opening the chutes to discharge the contents of the container. Apair of sliding guides adjacent the upper edge of the container, orother suitable means for allowing the repositioning of each cross bar 28b after they have been lifted, may be provided instead of hooks.

[0079] To prevent wear and tear on the ropes, a sacrificial pipe 28 c isprovided around each rope 28 c. At the base of pipe 28 c is attached aV-shaped plate 28 d. This V-shaped plate 28 d fits onto the upper edgeof cover 28 and provides additional support for the pipe or rope.

[0080] The cross bars 28 b are linked to each other by means of a pairof lengthwise bars 28 e so that hoisting the lengthwise bars 28 e ateither two or four points is sufficient to pull all the covers 28 up andopen the discharge chutes 27. Alternatively, a single bar 28 e isprovided at the centre of 28 b linking all the cross bars 28 b togetherand two hook engaging points on 28 e may then be used for opening all ofthe covers 28 simultaneously.

[0081] Variations of this embodiment are also possible. A variation isto provide covers with other cross-sections, for example, a partialcylindrical section. Another variation, as shown in FIG. 6f, is toprovide a slanting rope with each end attached to each of the twoattachment points on cover 28 with the centre part of the rope goingover a single cross bar 28 e. In order to help locate cross bar 28 e atthe centre of the container, at least two cross-bars 28 b are providednear the two ends of the container. Sacrificial pipes may be providedhere too around the ropes for reducing direct wear and tear of the ropesand indirectly the maintenance cost. Another variation is to do awaywith the rope but to use the sacrificial pipe or some other link, forexample, a cable or chain, for lifting the covers 28.

[0082] Another aspect of the invention is shown in FIGS. 7a-7 c. In thisaspect, open top or opened top containers are discharged by turning themupside down using a slewing apparatus 40.

[0083] A support structure 47 rotatably mounts a slewing structure 42,using a slew ring 41. An outer ring 41 a of slew ring 41 is fixedlymounted on the slewing structure 42. An inner ring 41 b of the slew ring41 is mounted on the support structure. A motor, gearbox and pinionassembly 48 is mounted on support structure 47 for turning slew ring 41a. Depending on the turning torque required, additional drive assemblymay be provided.

[0084] Slewing structure 42 has a base portion with twistlocks 45 forsupporting and affixing to the lower corner castings of a standardfreight container. It also has two vertically operable hydraulicactuators 43 at its sides for adjusting the heights of two verticallymovable clamping supports 44. The tops of these supports 44 havetwistlocks 46 for affixing to the upper corner castings of a standardfreight container, for clamping it against the base portion. The uppertwistlocks 46 are on arms which can rotate about vertical axes in thevertical portions of the clamping supports 44. They can be turnedthrough 90° to become clear of the container to be handled. This allowsthe container to be loaded vertically onto the slewing structure 42. Theangle of rotation could be slightly less or could be more, even allowing360°. The axis could even be horizontal to allow the arms to pivot in avertical plane.

[0085] The clamping supports 44 and upper twist locks 46 can also oralternatively pivot about a horizontal axis between first and secondpositions. In the first position support 44 is in a horizontal positionwith twistlock 46 directed downwards. Support 44 can also swing upwardto its second position and become clear of the way for a supplycontainer to be lowered vertically. Once the lower twist locks 45 haveengaged with the lower corner castings of the container, the supports 44and upper twist locks 46 are moved back to their first positions. Theyare then lowered by retracting actuators 43 before engaging with theupper corner castings. These operations can also be simultaneous orordered in other ways.

[0086] When a container is locked onto the slewing structure 42, theslew ring 41 is rotated to turn the slewing structure 42 and containerthrough substantially 180° to empty out its contents. It can then returnto its upright position back through the 180° it came or through theremaining 180°.

[0087] Support structure 47 can be mounted on the ground, on a trailer,on a forklift or on other suitable structures or vehicles.

[0088] As full containers can be very heavy, the preferred embodimenthas two such slewing apparatuses 40, one for each end. A preferredarrangement is shown in FIG. 7c, where two slewing assemblies 40 aremounted on a guide rail 49 to allow for variations in lengths ofcontainers. Although both are shown as being at adjustable positions,only one needs to be adjustable or on the rail.

[0089]FIG. 8a illustrates a containerised batching plant where variouscomponents are batched together in bulk, for instance for concrete. Eachtype of raw material used has its own feeding stack 100, which comprisesan assembly of containers stacked on top of each other. The bottom,discharge container 102 has an outlet chute 50 through which thematerial is transferred by a feeder, for example a conveyor, to ascaling station 60 before it is blended with other components in astation 70. From there it may be loaded into a mobile mixer or othercontainer. Station 70 may be a mixing device and/or a stock holdingdevice.

[0090] Depending on the amount of stock of material required, there isat least one stock container 104, 110 stacked above the dischargecontainer 102. For purposes of automation, a minimum material levelsensor 103 is provided near the base of the discharge container. Twostock containers 104, 110 are shown. The three containers hold a stockof the relevant material. Near the top of the stock container(s), is amaterial level sensor 105 for detecting the upper limit of the materialstock.

[0091]FIG. 8b shows a container 10 full of relevant materials on the topof the stack 100. It empties downwards into a pollution controlcontainer 120 which itself empties into the top-most stock container104. A retractable vibrator may be connected to the outside of thesupply container 10. This is used as and when necessary, for examplewhen the sand is wet and it is difficult for it to begin to fall bygravity or to minimise the amount of wet sand remaining on the insidesurfaces of the supply container.

[0092] The opening mechanism may be any shown earlier, e.g. a movablebase or by tipping the container upside down, using the slewingmechanism described earlier.

[0093] Discharge container 102 is exemplified by the differentembodiments of FIGS. 8c-8 e. Each drawing shows a side view of thecontainer and an end view. In each case the contents of the containerare moved to a discharge point by at least one screw.

[0094] The pollution control container 120 is shown in more detail inFIG. 8f. It is illustrated with two funnels 126. These collect anddirect the material falling into this container from above. Below and tothe sides of the funnels 126 are a plurality of exhaust fans 122.Separating each fan from the inner chamber of the container is a filter124 for catching fine dust particles in the exhaust air when the rawmaterial is released into the feed stack from container 10. Theundersides of the funnels 126, above the exhaust fans and filters act asdiverting shrouds for creating venting spaces for the fans and filters.Below each filter section is an enclosure 128 to trap dust particlesthat accumulate and fall off the filter. On the bottom of each enclosureis a valve 129 for periodic removal of the accumulated dust. This aspectof the invention provides for an abatement of dust pollution inherent inthis industry.

[0095] The fans 122 have a controller to operate them in switchablebi-directional rotations. For normal pollution control during thematerial discharge process, the fans 122 are operated as exhaust fanswith the impellers rotating in the first direction. To clear the dustadhering onto the filter and forcing the dust particle to collect inenclosure 128, the fans are operated as blowers with the impellersrotating in the reverse direction. With this feature, the filter isoperated with higher efficiency. Unnecessary machine breakdown due tofilter choking is avoided. This filter cleaning process may be carriedout periodically using automatic and interlocking control. Additionalvibrating means connected to the filter can also be used to improve thefilter efficiency.

[0096] The funnels in the pollution control container may divert theflow of materials to different storage points when a compartmentalisedcontainer 10″, 10′″ is used to supply different components.

[0097] Above the stations 60 and 70 is another pollution controlcontainer 80, as shown in FIG. 8a. As with the pollution controlcontainer 120 described earlier, there is a plurality of exhaust fans 84with a filter 86 separating the fans from the other chamber of thecontainer into which the raw materials are conveyed through chute 50.Above the filter and near the top centre of the container, there is aplurality of anti-choke cylinders 82. These cylinders are operable toshake off the dirt on the filter to prevent the filters from beingclogged up and become non-functional.

[0098] Depending on the reachable height of the handling facilities atthe batching plant, the feed stack 100 (comprising at least one stockcontainer, a pollution control container and the material supplycontainer) may be mounted directly above the stations 60 and 70. This isillustrated in FIG. 8b.

[0099] A pollution control container 120′ for use with the containerslewing apparatus 40 described earlier is illustrated from the side inFIG. 9a and from the top in FIG. 9b. This container 120′ is larger thanstandard containers. However it is balanced such that it can stack ontop of them and has twist locks suitably positioned for that purpose. Itis shown stacked on top of stack 100.

[0100] As in the other pollution control container described earlier,there is a plurality of fans and filters. Funnel 126′ is used to divertthe falling materials into the container below, such as the stockcontainer 104 or other containers in stack 100. This pollution controlcontainer 120′ has a large frame 132, which is shown in full in FIG. 9c,and encloses a pair of slewing apparatus 40, mounted on a guide rail 49.This is mounted onto the base 130 of frame 132 by means of twist locks.120′ also has retractable covers 131 at the top. These are closed when asupply container is loaded onto the slewing apparatus for it to beoverturned and the contents discharged. In this manner, the dust createdis contained inside 120′ and the filters trap the dust particles frompolluting the environment. As with the other pollution controlcontainers, the fans' rotation may be reversed periodically to clear thedust particles from clogging up the filters. Additional vibration meansmay also be used to improve the filter efficiency.

[0101]FIG. 10 shows yet another embodiment of a material feeding stack.A transtainer 150 moves along a set of rails and loads/unloads thematerial supply containers 10 onto/from on top of stock containers 104′.This transtainer 150 has a finite working height. In this case, thepollution control features of 120 are integrated into the upper part ofstock container 104′. Below container 104′ is a scaling conveyor 152 forfeeding the right amounts of the different material components to a linkconveyor(s) 153 for discharge into station(s) 70.

[0102] Each station 70 is enclosed in a pollution control enclosure120″. As with the other pollution control features, there may be aplurality of fans and filters for reducing dust pollution. Additionalvibration means may also be provided.

[0103] In accordance with the requirements of standard freightcontainers, they are stacked on top of each other with only the cornercastings of one container in contact with those of the other container.This means that the interface between containers is open and dustpollution can emanate from or enter into the interfacial gaps. Thereforeportable seals are provided to ensure that this pollution control meansis effective. FIGS. 11a-11 d illustrate the use of the seals 200, 210.In the case of seal type 200, these can be inserted from one side oncethe containers are in situ. Seals 200 are secured in position by meansof rotatable locks 201. These locks may be spaced at regular intervals,for example every 0.6 m. In the case of seal 210, these must be placedon a lower container before an upper container is placed.

[0104] Containers are usually filled with raw building materials usingrather messy bulk transfer, eg. by means of conveyors, clam shell bucketand cranes; shovel and tractor, etc. During such filling processes, rawmaterials unavoidably fall in between the containers. This is wasteful.Further, when this process is repeated several times it leaves mounds ofmaterial which make placing of the containers awkward and need removing.To minimise accumulation of materials, a cover 140, as shown in FIG. 12aand 12 b, is used. This clips containers together along their edges,with one cover covering two adjacent lengths, sides or other edges,thereby preventing material falling between them. A different cover 142is used to cover adjacent edges and corner castings. Otherwise thematerial may fall in there too and make it difficult to lock themproperly. Between them covers 140,142 can be used for every adjacentedge. For instance, along the top, several of cover 140 can be usedalong an adjacent length, depending on the lengths of the containers.

[0105]FIG. 13 illustrates a system for a container port forcontainerised handling of raw building materials. From a barge orcontainer ship 300, the containers are unloaded by means of a crane orother means (not shown), and unloaded onto prime movers 350 for transferto the stacking yard by another crane, typically a rubber-tyre gantrycrane 400. Within the crane operating area, is a concrete productionarea 500, for instance the batching plant described earlier. Eachcomponent of concrete is loaded into the scaling station 60 to determinethe amount before it is loaded into the station 70. This may include therelevant amount of water if it is required wet immediately. However, acustomer may order only the raw building materials. In this case, acontainer with the required type of raw materials is retrieved by thecrane, loaded onto a container truck for dispatch to the customer,without going through the concrete production area.

[0106] The containers from the barge or ship can also be known containermixers. In this case, the drums of the container mixers may already becarrying the right amounts of sand and aggregate to produce a commongrade of concrete. These are stacked away for stockpiling or are sent tothe production area 500 where water, cement and other additives arescaled and added to produce concrete. Alternatively, a separate groutingstation 600 is provided just to fill these container mixers.

[0107] It is also possible to use the container of this invention forshipping or transferring of other materials or general cargoes that canbe unloaded by opening of the base plate or sections of it. This generalcargo includes, but not limited to, any one or more of: goods onpallets; materials in drums or cartons; and machinery. This container,further comprising one or more doors at one or more of the ends and/orsides allow easy loading of goods.

[0108] While only a few embodiments of the apparatus and system havebeen described and illustrated, it is to be understood that manychanges, modifications and variations could be made to the presentinvention without departing from the scope of the invention.

1. A container for transferring bulk materials, being shaped anddimensioned in at least length and width to be handled as a standardfreight container and having a base, at least a portion of which isopenable for discharging contents of the container therethrough.
 2. Thecontainer according to claim 1, wherein said at least a portion of saidbase is slidably openable.
 3. The container according to claim 1,wherein said at least a portion of said base is hingably openable. 4.The container according to claim 1, wherein the openable portion of thebase comprises at least one pair of two cooperating halves, with onecooperating edge having an overlap over the other when said base isclosed.
 5. The container according to claim 4, wherein both halves ofthe or each pair are openable.
 6. The container according to claim 1,having at least one compartment, the or each compartment having at leastone lower section of reducing cross-sectional area, each leading to anopening, and a closure assembly for the or at least one opening, forreleasing or retaining the compartment's contents.
 7. The containeraccording to claim 6, wherein said at least a portion of said basecomprises an arcuate portion, operable to swing away from said opening.8. The container according to claim 6, wherein the or at least oneclosure assembly is pivoted.
 9. The container according to claim 6,further comprising hook means for moving the closure assembly to an openposition to allow the contents of its compartment to discharge.
 10. Thecontainer according to claim 6, having a plurality of said closureassemblies pivotably linked by linkage means so that opening one opensthem all.
 11. The container according to claim 6, wherein the or atleast one closure assembly has a perforated closure plate for allowingfluid to drain through.
 12. The container according to claim 11 furthercomprising a filter means disposed below the or at least one perforatedclosure plate for allowing fluid to drain through but keeping materialinside the container.
 13. The container according to claim 11, whereinthe or at least one closure plate is arcuate and is arranged to have asubstantially constant gap between it and its opening, as it is opened.14. The container according to claim 1, wherein said base comprises aplurality of sloped portions spaced apart from each other with thespaces between portions which slope down towards each other formingdischarge chutes.
 15. The container according to claim 14, wherein saidbase further comprises sloping portions along both ends of the containerto facilitate the discharge of the contents and prevent materials fromaccumulating at the ends during discharge.
 16. The container accordingto claim 14, further comprising a plurality of moveable covers on saiddischarge chutes operable to close and open the discharge 30 chutes. 17.The container according to claim 16, wherein said covers can be liftedto open the discharge chutes for discharge.
 18. The container accordingto claim 17, further comprising piston means for lifting said covers.19. The container according to claim 17, further comprising access meansto allow actuators to access and lift said covers from below thecontainer.
 20. The container according to claim 17, further comprisinglifting means attached to the upper sides of the covers to lift themfrom above.
 21. The container according to claim 20, wherein saidlifting means comprise flexible means chosen from the group comprising:cable, rope and chain.
 22. The container according to claim 1, beingcompartmentalised, the base of each compartment being openable andclosable independently of each other.
 23. The container according toclaim 1, also being suitable for transferring general cargo, including,but not limited to, any one or more of: goods on pallets; materials indrums or cartons; and machinery.
 24. The container according to claim 1,further comprising one or more doors at one or more of the ends and/orsides.
 25. The container according to claim 1, wherein at least aportion of the top is slidably or hingably openable.
 26. The containeraccording to claim 1, further comprising locking and securing means forsecuring the openable base portions in a closed position.
 27. Thecontainer according to claim 1, further comprising piston means foropening and closing the at least one openable portion of said base. 28.The container according to claim 1, further comprising seal means aroundthe at least one openable portion of said base, to prevent contaminationof the movement mechanism and to minimise wastage of materials. 29.Stewing apparatus for turning a container comprising: a supportingportion; a rotatable, container holding portion; and means for rotatingsaid container holding portion on said supporting portion; wherein saidcontainer holding portion comprises: a base portion for supporting andfastening to the lower part of a container; and arm means extensible ina first direction and having fastening means with an extent in at leasta second plane, orthogonal to said first direction, for fastening to theupper part of a container; wherein said fastening means is rotatablebetween a first position where it cannot fasten said container, whilstthe container is supported and fastened to said base portion, and asecond position, where it can fasten said container, whilst thecontainer is supported and fastened to said base portion.
 30. Apparatusaccording to claim 29, wherein, when said fastening means is in saidfirst position, a container can be placed for fastening to said baseportion or removed therefrom, and, when said fastening means is in saidsecond position, the fastening means obstructs a container from beingplaced for fastening to said base portion or removed therefrom. 31.Apparatus according to claim 29, wherein fastening means is rotatableabout at least a vertical axis.
 32. Apparatus according to claim 29,wherein fastening means is rotatable about at least a horizontal axis.33. Apparatus according to claim 29, wherein the base portion isarranged to support a container from below and said fastening means arearranged to fasten to a container from above.
 34. Apparatus according toclaim 29, wherein said base portion includes a pair of twistlocks forfastening to lower corner castings of a container; and said fasteningmeans includes a pair of twistlocks for fastening to upper cornercastings of a container.
 35. Turning apparatus for turning a standardfreight container over, comprising two slewing apparatus facing eachother, each as defined in claim
 29. 36. Turning apparatus according toclaim 35, further comprising rail means on which at least one of saidslewing apparatus is movable mounted for adjusting the relative distancebetween the container holding portions of the two slewing apparatus. 37.A system for producing a mixture of components, comprising: at least onestocking section having a stocking chamber for a component; and ascaling section for determining and delivering a scaled amount of eachcomponent; wherein said system is arranged such that a container may bestacked on top of said stocking section for replenishing said componenttherein.
 38. The system according to claim 37, further comprising asection for holding or blending said scaled components beforedischarging the mixture.
 39. The system according to claim 37, operablesuch that a container which is shaped and dimensioned in at least lengthand width to be handled as a standard freight container and having abase, at least a portion of which is openable for discharging contentsof the container therethrough may be stacked on top of said stockingsection for replenishing said component therein by opening said base anddischarging said material therethrough.
 40. The system according toclaim 37, further comprising at least one of a slewing apparatus and aturning apparatus on top of said stocking section, for turning acontainer over to replenish said component therein, wherein: the slewingapparatus comprises: a supporting portion; a rotatable, containerholding portion; and means for rotating said container holding portionon said supporting portion; wherein said container holding portioncomprises: a base portion for supporting and fastening to the lower partof a container; and arm means extensible in a first direction and havingfastening means with an extent in at least a second plane, orthogonal tosaid first direction, for fastening to the upper part of a container;wherein said fastening means is rotatable between a first position whereit cannot fasten said container, whilst the container is supported andfastened to said base portion, and a second position, where it canfasten said container, whilst the container is supported and fastened tosaid base portion; and the turning apparatus comprises two of saidslewing apparatuses facing each other.
 41. The system according to claim37 having a plurality of said stocking sections.
 42. The systemaccording to claim 37, wherein a material transfer means is provided tomove said component from the bottom of the or each stocking section tothe top of said scaling section.
 43. The system according to claim 37,wherein the or each stocking section includes a pollution controlsection for use between said container and said stocking chamber forabating particulate pollution as material is discharged into thestocking section.
 44. The system according to claim 43, wherein thestocking section is shaped, dimensioned in at least length and width andoperable as a standard fright container and includes said pollutioncontrol section.
 45. The system according to claim 37, furthercomprising a pollution control section disposed on top of said scalingsection for abating particulate pollution.
 46. The system according toclaim 43, wherein at least one pollution control section comprises atleast one exhaust fan separated from an inner portion of the saidsection by filter means.
 47. The system according to claim 46, whereinat least one pollution control section further comprises a plurality ofdiverting elements for creating venting spaces for said at least oneexhaust fan and filter means to operate.
 48. The system according toclaim 46, wherein the at least one exhaust fan is operable in onedirection as an exhaust fan for abating particulate pollution, or in thereverse direction as a blower to clear particulates from clogging up thefilter means.
 49. The system according to claim 48, wherein the at leastone exhaust fan is operable in the reverse direction at periodicintervals to clear dust particles from clogging up the filter means. 50.The system according to claim 48 further comprising vibration meansconnected to the filter means to improve efficiency.
 51. The systemaccording to claim 37, further comprising interfacial seal means forinterface gaps between said container and said stocking section and/orbetween said pollution control means and said stocking section.
 52. Thesystem according to claim 37, wherein at least one of the one or morestocking section, scaling section, mixing section, holding station andthe one or more pollution control sections is shaped, dimensioned in atleast length and width, transportable and stackable as a standardfreight container.
 53. The system according to claim 37, being a systemfor producing concrete.
 54. The method of producing a mixture using thesystem of claim 37, comprising the steps of: dropping components intostocking sections; transferring said components from said stockingsections into said scaling section; scaling said components and emptyingsaid scaled components into said mixing section; and blending saidcomponents.
 55. Cover means clipably attachable to adjacent edges ofadjacent freight containers to prevent materials falling therebetween.56. Cover means according to claim 55, including cover portions to covercorner castings.
 57. Interfacial seal means for sealing interfacial gapsbetween containers stacked on top of the other.
 58. A container,apparatus, system or method substantially as hereinbefore described withreference to and as illustrated in the accompanying drawings.